8. Brigadier Lethbridge-Stewart
Most of the Doctor’s companions have been ordinary people in their respective cultures. His first two companions (discounting his granddaughter) were schoolteachers. Clara is a nanny. Rose was a store clerk. Even characters from other cultures, and even the future, are usually ordinary people, at least when they join the Doctor. The Brigadier, however, is a British officer, often able to use his resources to come to the Doctor’s aid. This created a really cool aspect in the show, as it was less the Doctor and his idiotic companions getting captured and more of a team overcoming alien dangers. He first appeared with the second Doctor, but appeared primarily with the third, while he was exiled on Earth.